View Full Version : help with rockfords
12-02-2002, 01:08 AM
got all the wiring done and the amp works jus fine. Now i have another problem...which may seem strange. i have 2 new 12" RF Z's(4ohm each) in a bandpass box. i powerin w/ a lanzar vibe 220 amp which claims to put out ( 2x100 @ 4ohms) and (2x175 @ 2ohms). there are 4 speaker taps on the amp ( a + and - for left channel and same for the right channel). When i connected both subs to the left and right channel, im assuming the amp sees a 4ohm impedence, the output sounds a little weird kinda distorted and not totally in sync. it doesn't sound bad but jus not really clean.
im thinkin it might be the box. the plexiglass portion is facing u (if you place it infront of u) as 2 ports rest along the left and right sides. The woofers are not pointed directly straight at u, but more of an angle toward u and toward each other. kinda hard to explain but im tryin my best. the odd thing is that when i only use one channel (not bridged either) to hook up to jus one of the woofers (doesn't matter which one) they sound alot better. Louder and crisper. So my q is why when i hook up both they dont sound good?! plus i need some detailed help on parallel wiring.. cuz i tried hookin both + and - spades from both woofers onto jus one channel so i left one channel empty and it didn't sound louder. THANKS ALOT.
12-02-2002, 04:57 PM
Already answered this on another board...oh well.
Try facing the plexi down....so the subs fire downwards into the floor...put the plexi part of the box on the floor - cut down all the crappy noise and plexi flexing for me:)
Also...are you sure that the subs are 4 ohm? I know rocford makes the punch z's in an 8 ohm also. Rockford punchZ's typicaly like 1.25cubicft per woofer, sealed & halfway stuffed with polyfill. I would also bridge that lanzar amp.
12-22-2002, 02:00 AM
now, how would i bridge it cuz i need to have two channels going to two subs. cuz right now the (+) of one sub is connect to the - on the amp and (-) on the sub to the + on the amp; and the other sub is in phase ( + to +, - to -). so all four speaker outs are used. if i was to bridge it and only use the outer two, (+)(-), how would i finish wiring it to the subs? yea and i had to wire one sub in phase and on out since i have a bandpass and the subs are slanted slighty toward each other and cancellation takes effect if i wire both with the same polarity.. i would love to bridge it but how? thanks...
Before you do all of this, MAKE SURE that you have the right size power wire, and the right size box.
First...Make sure that the gain on the amp is turned all the way down.
Then...Take the positive output from the left channel of the amp and connect it to the positive of one sub, then run another wire from the positive of the sub to the positive of the next sub.(so both sub's positives are connected to the positive of the left channel.)
Next...Take the negative output from the right channel of the amp and connect it to the negative of one sub, then run another wire from the negative of the sub to the negative of the next sub.(so both sub's negatives are connected to the negatives of the right channel.)
Your amp will then have 2 terminals that aren't being used (and this is OK). The negative of the left channel and the positive of the Right channel will not be used at all.
After you do all of this check the cross-over on the amp and set it to about 80Hz.
Then turn your deck up to the the maximum volume that you usually play it at.
After the deck is turned up, SLOWLY turn the gain of the amp up until you get loud sound without distortion.
This is how you bridge an amplifier to run a 2ohm Mono load.
If you have any problems or don't understand E-mail me@ email@example.com
12-24-2002, 12:20 AM
ic..but u kno how the subs were connect one in phase and one out of phase...after i bridge it, will i have the cancelation problem?
None, the subs used to cancell because they were wired in stereo, so each sub hit at different times...when you bridge an amp, it runs in mono, which has both subs hitting at the same time.....No cancellation.
12-24-2002, 07:03 PM
yea it seemed to work well; until the protect led came on on my amp..:) ugh my amp (lanzar v220) claims to be bridgeable down to 2 ohms. but not sure bout 2 ohms mono. For future reference, what is the difference between bridged 2 ohm mono and bridged 2 ohm stereo? is it jus mono is bridged to 1 sub and stereo is to two subs? also what about correct positioning of a bandpass box. it houses 2 12" rfs that slightly face you and each other. each chamber has two ports also facing you and the subs are aimed in a sealed plexiglass front. I am using this setup in a sedan currently so it has to penetrate a back seat. Now must I face toward the rear of the vehicle? what is the difference?
What size power wire are you running, and how big is your alternator.
I am an authorized Lanzar dealer, and i have Never had a problem running them at 2 Ohms mono, also how far is your gain turned up?
12-25-2002, 09:42 PM
yea jmac was right its stable down to 2 ohms Stereo... um... 8 gauge...not too sure with alternator. no dimming however and it the gain is turned up about 25%...between mid way and minimum. so one question i have is how would i be able to bring it down to 2 ohm STEREO, use DVC subs? if so how would the setup work...thanks guys
At 2 ohms mono, the amp is trying to draw more current than the wire can supply, It will run fine with 4 awg wire.
12-26-2002, 08:22 PM
ok how much are 4 g's? jus the power itself...cuz i wouldn't need to change netin else would i? thanks
Power and ground , it should be pretty cheap....Also, how far do you have the gain turned up?
12-26-2002, 08:55 PM
brige the amp, and (im assuming this is a 3-chamber banpass box) reverse the polaritys of one of the subs to create the push-pull effect...
I / \ I
I / \ I
I Sub Sub I
I / \ I
I____ / \______I
Both of the subs right now are pushing each other.
Reverse the polarity (put the + to the - and..the - to the + )
Now one of the subs will move back first and the other one will move
forward first (its not so hard on the subs) Make Sense???
Hope this helps! :)